Method of making siftproof bags



July 30, 1940. G. w. POPPE 2,209,901

METHOD OF MAKING SIFTPROOF BAGS Original Filed Sept. 15. 1937 2Sheets-Sheet 1 3 Inventor July 30, 1940. a. w. POPPE 2,209,901

' METHOD OF MAKING SIFTPROOF BAGS Original Filed Sept. 15, 193' 2Sheets-Sheet 2 Snvcntor Patented July 30, 1940 UNITED STATES PATENTOFFICE 165,693; Divided and this application April 7, 1939, Serial No.266,478

3 Claims.

This invention relates to a method of producing a siftproof bag of thecharacter known in the art as a gusset, bellows fold, or square bottom10 Since the method in commercial production is practiced on a bagmachine, it will best be understood when described in connection withsuch machine.

In the accompanying drawings, Figure 1 is a top plan view of portions ofa b'a machine of known construction, and showing how a web of paper iscut and foldedinto a tube, from which bag sections are successivelyformed;

Figure 2 is a bag section, after severance from the tube, but prior tofolding over of the bag bottom; I

Figure 3 is a perspective view showing the bag in partly openedcondition to more clearly indicate its general construction; and

Figure 4 is a side elevation, partly broken away, of so much of amachine of known construction as will sufficiently illustrate how mymethod is practiced and the bag produced at the high speed necessitatedby commercial requirements.

In order that the description may accord with that of the parent case, Ihave used the same reference characters to designate the same parts inthe present divisional application as in the parent case.

Referring to Figures 1 and 4, a .web of paper ll carried by a roll I!passes from said roll over,

-convenience, in manufacture and assembly, the

knife is preferably made in sections and each section may beindependently adjustable in the" cylinder 20, although, of course, aknifemight be constructed in one piece-,and shaped'ss shown.

Assuming a sectionalconstruction, the center section 22, Figure 1 makesa. series of perforations in theweb which determine the top and bottomedges of the plain wall of a bag portion prior to folding ths bottom.Sections 24, adjacent the sec- 55 tion 22' form the top and,bottom edgesof oneplyoz the bellows fold. The sections 24 are in alignment with eachother but are stepped from the section 22. The sections 26 are likewisein alignment with each other but are stepped from the sections 24, thesesections 26 forming the top and bottom edges of the other ply of thebellows fold. Sections 28 are in alignment with each other but eachstepped from the adjacent section 26 and form the bottom and top edges'of the seam wall of the bag when the web is folded into a tube. The"lines of perforations 22a, 2 la, 26a and 28a, Figure 1 show thecondition of the web after the knife sections correspondingly numbered,have acted upon it as the web passes over the roller it.

After the web is perforated as above described, it passes under a roller30, Figure 4 and under a former 32 about which it is folded by the usualmechanism to produce bellows folds between the bottom plain wall I,Figure 3, and the upper seam wall 2. The seam wall is produced byfolding the pasted portion i5 over onto the opposite longitudinal edgeof the web as indicated in the lower portion of Figure 1.

The folded tube and web ,are fed through the machine by means of theusual feed rollers 34, Figure 1-, from which rollers the tube passesover the clamp cylinder 36 having the usual clamps for receiving thebottom folded portion of the tube, such fold being produced by the usualtucker blade' as carried by a roller 40. This roller also carries one ormore paste bars 42 which supply the paste to the seam wall of the bagjust after the action of the tucker blade to tuck the end of the tubeinto the clamp. The cylinder 36 is rotated in such a manner that theperipheral speed is greater than the peripheral speed of the feedrollers 34 and therefore when the tucker blade tucks the end of the bagtube into the clamp a bag tube section is severed from the main tube. Asevered section is indicated at the lower portion of Figure 1 which alsoshows the bottom of the section folded over and pasted, thereby formingthe completed article. Figure 2 shows a section somewhat enlarged fromthat shown in Figure land prior to the pasting of the The line of fold.however, is shown along the line a-a and the paste area is"indicated' bythe reference character.

male completed bag therefore the lower edge soTheendoftheplainbaswallindicatedatlis likewise oflset from the edges oithe bellows told 3 and is pasted down on the seam wall. The lower 'edgeof the seam wall is folded over on itself and this edge is offset fromthe edges 4.

It will be noted that the paste area 6, extends from a position belowthe edge of the turned-over portion 5 and almost to the end of theturnedover portion 1, and that the ends of both bellows folds as well asthe fold 5 are pasted onto. the seam wall. With this construction athoroughly siftproof bag of the bellows type is produced.

The machine may be driven by a motor indicated diagrammatically at 44having a transmitting shaft 46 on the end of which is a bevel gear 48meshing with a smaller bevel gear 50 on a shaft 52 which carriessuitable gears for driving the clamp cylinder 36 at the proper speed.

A st'ub shaft 54 also projects from the motor casing and throughsuitable gears drives a chain 55 whereby the cylinder 20 carrying theknives is driven once for each bag to be produced.

, The machine being well known has not been described in detail but itsgeneral operation only is set forth in order that a practical manner of.practicing my method may be sufliciently disclosed. v

It is to be understood, however, that variations may be resorted to inthe method and machinery used provided such variations are within thescope of the invention and without departing from the spirit thereof.

What I claim is: I

,l. The method of making a bellows fold siftprooi' bag which consists inperforating a continuously advancing web .of paper, along trans. verselines, said lines defining the ends of a section that is to constitute abag, the transverse perforations defining the ends of each adjacentiplies of bellows iold being ofl-set from each other and also oil-setfrom the perforations defining .the walls of a bag section to which eachis adjacent, folding the web'into a bellows tube, severing a sectionfrom the tube along said perforated lines, and closing the bottom of thesection to .complete the bag.

lineswhich lines define one end of a bag wall and one end of the pilesof the bellows fold, the lines defining the end of one plyot the bellowstold being ofiset. from the other ply of the fold, the ends of bothplies being off-set from said line defining the end of' the bag wall.

GEORGE W. POPPE.

-Patent- No. 2,209,901.

CERTIFICATE OFVCQRRECTION.

I Jul 0, 191p.- GEORGE w. PoPPE;

It is hereby certified thatthe above numbered petent was erroneouslyissued to the inventor, said PoPPl'fl' whereas said patent shouldhavebeen isued to' --Eqnitab1 e Paper Bag 00. Inc. of Brdeklyn, NewXork, a corpora.-

tion 91 New York as a ssignee ofthe entire interest therein as shown bythe record of assignments in this offipe; a t at the s aid LettersPatent shouldbe readyvith this cerrection therein that the same mayconform to the record of the ease in thePatent Office.

signed an sea led this 8th day of october, A. D 191;.0.

Henry Van Arsdale, (Seal) Aeting Confinissiener of Patents;

